SF 

SIO 

UC-NRLF 


B   3   im    17T 


CATTLE -ITiilVER   TIGIIS 

By  fV.P,  dllenberger 

and  H.:i.  Ghapin 

U.^.D..i.  Bui.  1057       January  1920 


I  \  FARMUQS'  BULLETIN  1057 

I!!   \  UNITED  STATKS  DKP/u^TMRMT  OP  AGRICULTURE 


jTLr  rcvcR 


^M^#"^ 


TICKS 

METHODS  of  EEADICATION 


4. 


^^5^. 
% 


RY-BfPPING 
L  TO  PROS© 


Agric. -Fo-strv .  Mail)  Ubc«F  ^^^^^  ^^  ^ 


THE  ERADICATION  of  the  cattle  tick  from  the 
Southern  States  is  a  problem  of  prime  impor- 
tance to  the  agricultural  welfare  of  the  entire 
country. 

The  elimination  of  the  tick  will  give  a  verj'  great 
impetus  to  the  cattle  and  dairy  interests,  especially 
of  the  South,  ^vhere  agriculture  will  be  placed  on  a 
more  scientific  and  profitable  basis. 

Although  the  eradication  of  the  tick  will  be  of 
greatest  advantage  to  the  States  in  which  ticks  arc 
found,  the  benefits  will  be  enjoyed  also  by  all  other 
sections.  In  consequence  the  problem,  in  large 
measure,  is  one  of  national  importance. 

A  number  of  publications  on  the  cattle  tick,  its 
habits,  and  methods  of  eradication  have  been  issued 
by  the  United  States  Department  of  Agriculture  and 
by  various  investigators  in  the  Southern  States. 
This  bulletin,  prepared  for  the  use  of  farmers,  stock- 
men, and  other  interested  persons,  brings  together, 
from  the  various  sources,  practical  and  useful  infor- 
mation regarding  the  tick  and  its  eradication.  It 
supersedes  Bureau  of  Animal  Industry  Circular  207 
and  F'armers'  Bulletins  498  and  603,  which  are  no 
longer  available  for  distribution. 


Contribution  from  the  Bureau  of  Animal 

Indust 

ry 

JOHN  R 

MOHLER.Cl.icf 

Wauhiugton 

D.C. 

Issuod  October, 
Revised   Juiiiiur 

1919 
y.  1920 

CATTLE-FEVER  TICKS  AND  METHODS  OF 
ERADICATION. 

W.  P.  Ellenbebger  aud  Kocekt  M.  Ciiapin,  Bureau  of  Animal  InduHtnj} 


CONTENTS. 


Progress  in  tick  eradication 3 

Reasons    for    eradicating    the    cattle 

tick 4 

Life  history  of  the  tick 6 

Development  on  the  ground G 

Development  on  cattlo 11 

Summary  of  life  history 11 

Methods  of  eradication 11 

Dipping 12 

Pasture  rotation 17 


Page. 

Arsenical    dips 21 

Properties  of  substances  used  in 

making  arsenical  dips 21 

(ieneral  composition  of  dips 23 

Making  the  S-B  dip 24 

Making  the  boiled  dip 26 

Diluting  the  dip  to  foi-m  a  bath_  27 
Replenishing  the   bath   and   cor- 
recting its  strength 29 

Precautions  in  the  use  of  arsenic 

and  arsenical  dips 31 


PROGRESS  IN  TICK  ERADICATION. 

THP]  Bureau  of  Animal  Industry,  in  cooperation  with  the  State 
authorities,  is  conducting  tick-eradication  work  in  the  region 
infested  by  the  cattle  tick,  as  shown  in  the  map  (figure  1).  From 
1906,  when  this  cooperative  work  was  first  undertaken,  to  December 
1,  1919,  a  total  of  509,084  square  miles  was  released  from  Federal 
quarantine  which  had  been  established  to  control  the  situation,  and  in 
considerable  additional  aiea  the  work  is  well  under  way.  The  terri- 
tory already  released  from  quarantine  is  nearly  equal  to  the  combined 
areas  of  the  following  block  of  States:  Virginia,  Kentucky,  Tennessee, 
North  Carolina,  South  Carolina,  Georgia,  Florida,  Alabama,  Missis- 
sippi, Al^.lnsas,  and  Louisiana.  This  record  alone  should  be  ample 
proof  of  the  feasibility  of  eradicating  the  tick  from  the  entire  infested 
area,  and  is  evidence  of  the  effectiveness  of  the  methods  adopted. 

The  methods  of  eradication  have  been  improved  upon  from  time 
to  time  as  new  facts  became  known,  and  it  may  be  stated  that  the 
methods  have  reached  such  a  degree  of  perfection  and  have  had 
such  a  wide,  practical  test,  that  the  question  of  how  to  eradicate  ticks 
is  no  longer  an  essential  part  of  the  problem.  The  main  part  of  the 
task  is  to  secure  hearty,  vigorous,  and  conscientious  cooperation  of 
the  people.  In  other  words,  the  work  will  progress  just  as  rapidly 
as  the  people  desire  that  it  shall. 

1  Author's  note. — Much  of  the  information  in  this  bulletin  relating  to  the  life  history 
of  the  tick  and  methods  of  eradication  has  been  taken  almost  verbatim  from  Farmers' 
Bulletin  408,  by  H.  W.  Graybill,  with  slight  revisions  by  B.  H.  Ransom,  chief  of  the 
Zoological  Division  of  the  bureau.  Robert  M.  Chapin,  of  the  Biochemic  Division,  pre- 
pared that  portion  of  the  bulletin  relating  to  arsenical  dips. 

3 


4  Fann^h^  Bulletin  ip57.  '  - 

REASONS  FOR  ERADICATING  THE  CATTLE  TICK. 

Various  kinds  or  species  of  ticks  occur  on  cattle  in  the  Southern 
States,  but  the  one  that  chiefly  concerns  us  here  is  that  commonly 
called  the  "cattle"  or  "Texas-fever"  tick  {Margaropus  annuhfus). 
It  is  the  one  most  f req.uen±ly  found  on  cattle  in  the  South  and  is 
much  more  abundant  than  any  of  the  other  species.  When  th6  losses 
caused  by  this  parasite  are  once  thoroufjhiy  understood  by  farmers 
and  stockmen  arguments  in  favor  of  tick  eradication  will  not  be 
needed.  Some  of  the  losses  are  not  directly  noticeable  and  conso- 
quentl}^  make  little  impression,  vehile  others  properly  chargeable  to 
the  tick  are  frequently  attributed  to  other  causes. 

It  is  hardly  necessary  to  emphasize  that  the  tick  is  something  more 
than  a  simple  parasite  drawing  blood  from  its  "  host^'  the  name  com- 
monly given  the  animal  on  which  a  parasite  lives.  The  tick  is  also 
the  carrier  of  a  dangerous  microorganism,  or  germ,  which  it  trans- 
mits to  the  blood  of  cattle,  thus  causing  a  disease  known  by  many 
names,  among  which  are  Texas  fever,  tick  fever,  splenetic  fever,  and 
murrain.^  Without  the  tick  there  can  be  no  tick  fever,  and  by  stop- 
ping the  spread  of  the  tick  beyond  its  natural  bounds  the  fever  has 
been  prevented  from  waging  destruction  among  northern  cattle, 
which  are  especially  susceptible  to  the  disease.  In  order  to  restrict 
the  distribution  of  the  tick  the  National  and  State  Governments 
maintain  quarantine  areas,  marking  the  boundaries  between  the 
States  or  portions  of  States  harboring  the  pest  and  those  that  do  not 
(see  figure  1).  Cattle  may  be  moved  out  :f  the  quarantined  areas 
only  in  accordance  with  the  regulations  of  the  Secretary  of  Agricul- 
ture to  prevent  the  spread  of  splenetic  fever  of  cattle. 

The  Bureau  of  Animal  Industry  has  received  hundreds  of  letters 
from  farmers  and  other  interested  persons,  all  residents  of  the  south- 
ern territory  which  has  been  freed  from  ticks,  testifying  to  the  bene- 
fits derived  from  the  destruction  of  the  pest.  The  consensus  of 
opinion  in  these  letters  indicates  that  on  the  average  cattle  are  en- 
hanced in  value  about  $10  a  head,  they  weigh  one-fifth  more,  they 
grade  one- fourth  better,  and  they  are  safe  from  tick  fever  and  from 
the  shrinkage  which  it  causes.  It  is  also  stated  that  the  cattle  indus- 
try in  the  South  is  increasing,  that  there  is  an  increase  in  improved 
blood,  that  the  milk  3'^ield  of  coavs  is  increased  about  one-fourth,  and 
that  there  is  an  increase  of  forage  crops  and  silos. 

The  South  needs  more  and  better  live  stock  and  a  larger  and  bettor 
dairy  industry,  and  these  objects  are  being  promoted  greatl}'  by  the 
destruction  of  the  tick.  More  than  that,  the  increased  production  of 
live  stock,  by  reason  of  its  important  influence  in  maintaining  and 

1  For  Information  on  this  disoasp  niul  how  it  Is  trnnsmitti-il  hy  tltks,  soc  I''armiT.s'  lUil 
letla  569,  "  Texas  or  Tick  Fever." 


f 


Catlle-Fever  Ticks. 


6  Farmers'  Bulletin  1057. 

improving  soil  fertility,  is  of  distinct  benefit  in  increasing  the  j'ield 
of  field  crops.  An  incidental  though  important  advantage  of  stock 
raising  and  dairying  will  be  found  in  the  distribution  of  the  farmer's 
income  throughout  the  year,  enabling  him  to  live  on  a  cash  basis. 
Thus  the  benefits  that  will  accrue  to  southern  agriculture  through 
exterminating  the  cattle  tick  will  be  far-reaching. 

LIFE  HISTORY  OF  THE  TICK. 

To  carry  out  methods  of  eradication  successfully  it  is  necessary  to 
know  the  life  history  of  the  tick  and  the  influence  of  temperature, 
moisture,  and  other  climatic  conditions  on  the  various  stages  of  its 
existence.  In  following  the  discussion  of  these  matters,  the  reader 
is  asked  to  bear  in  mind  that  whenever  the  term  "  tick  "  or  "  cattle 
tick "  or  "  fever  tick "  is  used  it  refers  to  the  one  species  or  kind, 
Margaropus  annulatus.^  The  fever  tick  is  sometimes  confused  with 
a  number  of  other  ticks  occasionally  found  on  cattle  which,  so  far 
as  concerns  the  transmission  of  Texas  fever,  are  entirely  harmless 
to  them.  Some  of  these  ticks  are  illustrated  in  figures  2  and  3,  which 
will  help  the  reader  to  distinguish  between  the  various  kinds. 

Cattle  are  the  usual  hosts  for  the  fever  tick.  Frequently,  horses, 
mules,  deer,  and  sometimes  even  buffaloes  and  sheep  serve  as  hosts. 
But  none  of  the  latter  animals,  with  the  possible  exception  of  deer 
and  buffaloes,  are  susceptible  to  tick  fever;  consequently  they  suffer 
from  the  tick  as  a  simple  parasite  and  not  as  a  transmitter  of  dis- 
ease. So  far  as  deer  and  animals  other  than  cattle,  horses,  and  mules 
are  concerned  no  consideration  need  be  given  them  in  practical  tick 
eradication.  In  the  case  of  horses  and  mules,  however,  it  is  often 
necessar}^  to  treat  them  the  same  as  cattle. 

The  tick  spends  only  a  part  of  its  life  on  the  body  of  the  animal; 
the  rest  of  the  development  occurs  on  the  pasture. 

DEVELOPMENT   ON  THE  GROUND. 

In  tracing  the  life  history  of  the  cattle  tick  it  is  convenient  to  be- 
gin with  the  large,  plump,  olive-green  engorged  female  tick  (figure 
4),  about  half  an  inch  in  length,  attached  to- the  skin  of  a  cow.  Dur- 
ing the  few  preceding  days  she  has  increased  enormously  in  size, 
as  a  consequence  of  drawing  a  large  supply  of  blood. 

When  fully  engorged  she  drops  to  the  gi-ound  and  at  om'o.  espe- 
cially if  the  weather  is  warm,  begins  to  search  for  a  hiding  place 
on  moist  earth  beneath  leaves  or  any  other  litter  which  may  serve 


iTlie  reader  doslriiiK  fullor  information  on  tlio  lifo  lilstory  of  tlio  catllo  tU'k  is  rof»>rn'(i 
to  Bulletin  72,  of  the  Hureaii  of  h:ntomoloK.v.  and  lUilletln  l.SO.  Hiiroau  of  Animal  Indus- 
try,  U.  S.  Department  of  Agriculture,  whieli  may  l)e  obtained  from  the  Superintendent  of 
Documents,  Government  Printing'  Odice,-  WashlnKlon,  D.  (',,  for  15  and  10  e.-nts.  respo 
tively. 


f^ 


Cattle-Fever  Ticks.  7 

as  a  protection  from  the  sun  and  nunierons  enemies  or  shield  her 
from  unfavorable  conditions.  The  female  tick  may  be  devoured  by 
birds,  or  destroyed  by  ants,  or  may  perish  as  the  result  of  low  tem- 
perature, absence  or  excess  of  moisture,  and  many  other  unfavorable 
conditions ;  so  that  many  which  fall  to  the  ground  die  before  they  lay 
eggs. 

During  the  spring,  summer,  and  fall  months  egg  laying  begins 
in  from  2  to  20  days,  and  during  the  winter  months  in  from  13  to 
98  days,  after  the  female  tick  has  fallen  to  the  ground.  The  eggs 
are  small,  elliptical-shaped,  at  first  of  a  light-amber  color,  later 
changing  to  a  dark  brown,  and  are  about  one-fiftieth  of  an  inch  in 
length.  As  the  eggs  are  laid  they  are  coated  with  a  sticky  secretion, 
which  causes  them  to  adhere  in  clusters  and  no  doubt  keeps  them 
from  drying  out.  During  egg  laying  the  body  of  the  mother  tick 
gradually  shrinks,  and  finally  is  reduced  to  about  one-third  or  one- 
fourth  its  original  size.  Egg  laying  is  greatly  influenced  by  tem- 
perature, being  retarded  or  even  arrested  by  cold  weather.  In  the 
summer  time  egg  laying  may  be  completed  as  soon  as  4  days  after  it 
has  begun,  or  by  the  end  of  about  a  week  after  the  tick  has  dropped 
to  the  ground.  It  has  been  observed  that  if  the  ticks  drop  in  the  fall 
of  the  year  the  egg-laying  process  may  continue  for  as  long  as  151 
days.  A  tick  may  deposit  from  a  few  hundred  to  more  than  5,000 
eggs,  and  when  egg  laying  is  completed  the  mother  tick,  having  ful- 
filled her  purpose,  dies  in  a  few  days. 

After  the  eggs  have  been  laid  they  must  undergo  a  period  of  in- 
cubation before  they  are  ready  to  hatch.  The  period  may  be  as  short 
as  19  days  in  the  summer,  or  as  long  as  200  days  if  the  fall  and 
winter  seasons  are  involved.  When  incubation  has  been  completed 
there  issues  from  each  egg  a  small,  oval,  six-legged  larva  or  seed  tick, 
at  first  amber-colored,  later  changing  to  a  rich  brown.  After  crawl- 
ing slowly  over  and  about  the  shell  from  which  it  has  emerged,  it 
usually  remains  more  or  less  quiet  for  several  days,  after  which  it 
shows  great  activit}^,  especially"  if  the  weather  is  warm,  and  ascends 
the  nearest  vegetation,  such  as  grass,  herbs,  and  even  shrubs. 

Since  each  female  lays  an  enormous  mass  of  eggs  at  one  spot,  thou- 
sands of  larvse  ma}'  appear  in  the  course  of  time  at  the  same  place. 
The  young  ticks  will  ascend  the  near-by  vegetation  and  collect  on 
the  leaves  and  other  parts  of  plants.  This  instinct  of  the  seed  ticks 
to  climb  upward  is  a  very  important  adaptation  to  increase  their 
chances  of  reaching  a  host.  If  the  vegetation  on  which  they  rest  is 
disturbed  they  become  very  active  and  extend  their  long  front  legs 
upward  in  a  divergent  position,  waving  them  violently  in  an  attempt 
to  seize  hold  of  a  host. 

During  its  life  on  the  pasture  the  seed  tick  takes  no  food  and  con- 
sequently does  not  increase  in  size,  and  unless  it  reaches  a  host  on 


V 


Fig.  2. — Vurloiis  ticks  Unit  Infest  culllu.  1.  iM.-itiii-f  rt'iiialc  cattle  tick,  eiiliir;;ed  ;  \ii.  same, 
naluial  size;  Ih,  head  and  shield  of  same,  mafjrnilli'd  l.'i  limes.  L',  .Mature  female  castor- 
hean  tick,  enlai'Kod  ;  'Ja,  same,  natural  slz»' ;  li(j,  head  and  shield  of  same,  inaKnllled  l.'i 
times.  .'!.  Mature  female  net  lick,  enlai'Ked  ;  ;i(/,  sanu-,  natural  sl/.e  :  lUi.  head  and  shield 
of  same,  nniKnilled  l.l  times.  4.  Mature  female  dof;  or  wood  tick,  enlarged;  -id.  same, 
natural  size  ;  4b,  head  and  shield  of  same,  muKnllied  ir>  times. 

8 


I''iG.  3. — Various  ticks  that  infest  cattle.  5.  Mature  female  Lone  Star  tick,  enlarged  ; 
5a,  same,  natural  size  ;  ob,  head  and  shield  of  same,  magnified  ir»  times.  6.  Mature 
female  ear  tick,  enlarged  ;  6«.  same,  natural  size  :  ()?>,  head  of  same  protruding  from 
beneath,  magnified  15  times.  7.  Alature  female  chicken  tick,  enlarged;  7o,  sameT  natu- 
ral size  ;  76,  upper  portion  of  same,  head  invisible,  magnified  10  times.  8.  Mature  fe- 
Tiale  European  dog  tick,  enlarged  ;  8a,  same,  natural  size  ;  8&,  head  and  shield  of  same, 
•lagnified  15  times. 

155463°— 19 2  9 


10 


Farmers'  Bulletin  W57. 


wliich  to  live  as  a  parasite,  it  dies  of  starvation.  The  endurance  of 
seed  ticks  is  very  great,  however,  as  they  have  been  found  to  live 
more  than  8  months  during  the  colder  part  of  the  year.  For  example, 
it  is  known  that  in  the  case  of  female  ticks  that  dropped  to  the 
ground  August  14  and  deposited  eggs  that  began  to  hatch  September 


SEED  TICKS 


f 


NVMPH 


ILTMALE    lADuffS-EMALE 


ADULT  MALE 


ENGORGED  ADULT   FEMALE 


FEMALE  LAYING  EGGS 


Fig.  4. — Tcxixs-fevt-r  tickis,  iniiKUiliod  5  tiiui's. 

9,  all  the  seed  ticks  from  the  eggs  were  not  dead  uutil  the  l\)lU)wing 
May  13,  24G  days  after  hatching  began,  or  274  days  after  the  fenudes 
dropped  from  the  cattle.  Fortunately,  however,  seed  ticks  are  not 
able  to  live  nearly  so  long  during  warm  weatlier  ami  die  within  a  few 
months  in  the  summer. 

1 


Cattle-Fever  Ticks.  11 

DEVELOPMENT  ON  CATTLE. 

The  parasitic  part  of  a  tick's  life  begins  when  the  larva  or  seed 
tick  reaches  a  favorable  host,  such  as  a  cow.  The  tick  crawls  up 
over  the  hair  and  commonl}^  attaches  itself  to  the  skin  of  the  es- 
cutcheon, the  inside  of  the  thighs  and  flanks,  or  to  the  dewlap. 
It  begins  at  once  to  draw  blood  and  soon  increases  in  size.  In  a  few 
days  the  young  tick  changes  from  a  brown  color  to  white,  and  in 
from  5  to  12  days  molts  or  sheds  its  skin.  The  new  form  has  8 
legs  instead  of  6  and  is  Imown  as  a  nymph. 

In  from  5  to  11  days  after  the  first  molt  the  tick  again  sheds  its 
skin  and  becomes  sexually  mature.  At  this  stage  for  the  first  time, 
males  and  females  can  be  distinguished  with  certainty.  The  male 
emerges  from  his  skin  as  a  brown,  oval  tick,  about  one-tenth  of  an 
inch  long.  He  has  reached  his  growth  and  goes  through  no  further 
development,  but  later  he  shows  great  activity,  moving  about  over 
the  skin  of  the  host.  The  female  at  the  time  of  moMing  is  slightly 
larger  than  the  male.  She  never  shows  much  activity,  seldom  mov- 
ing far  from  her  original  point  of  attachment.  She  still  has  to  un- 
dergo most  of  her  growth.  "After  mating,  the  female  increases  very 
rapidly  in  size  and  has  been  known  to  become  fully  engorged  as 
early  as  48  hours  after  the  second  molt,  but  usually  at  least  4  days 
are  required  for  her  engorgement.  Commonly  this  period  lasts  from 
about  a  week  to  as  long  as  25  days.  In  exceptional  cases,  the  time 
that  elapses  betAveen  the  attachment  of  the  tick  as  a  seed  tick  and 
its  dropping  from  the  animal  as  a  fuUy  engorged  female  may  be 
less  than  20  days,  but  generally  it  is  3  weeks  or  a  little  more. 
The  greatest  length  of  time  that  a  tick  has  been  observed  to  stay 
on  an  animal  is  66  days. 

SUMMARY  OF  LIFE  HISTORY. 

To  sum  up,  on  the  pasture  there  are  three  stages  of  the  tick — the 
engorged  female,  the  Qgg.,  and  the  larva  or  seed  tick;  and  on  the 
host  animal  are  also  three  stages — the  larva  or  seed  tick,  the  nymph, 
the  sexually  mature  adult  of  both  sexes,  and  in  addition  the  engorged 
condition  of  the  female. 

METHODS  OF  ERADICATION. 

In  undertaking  measures  for  eradicating  the  tick  it  is  evident 
that  the  pest  may  be  attacked  in  two  locations,  namely,  the  pas- 
ture and  the  cattle.  Animals  may  be  freed  of  ticks  in  two  ways. 
They  may  be  treated  with  a  disinfectant  that  will  destroy  all  the 
ticks  present,  or  they  may  be  pastured  at  proper  intervals  on  tick- 
free  fields  until  all  the  ticks  have  dropped.  The  method  of  freeing 
cattle  from  ticks  by  applying  a  solution  that  kills  the  ticks  is  the 


12  Farmers'  Bulletin  1057. 

method  generally  used.  The  pasture-rotation  method  is  not  only 
more  complicated  but  the  necessary  tick-free  fields  are  seldom  avail- 
able. 

In  freeing  pastures  the  method  followed  may  be  either  direct  or 
indirect.  The  direct  method  consists  in  excluding  all  cattle,  horses, 
and  mules  from  pastures  until' all  the  ticks  have  died  from  starva- 
tion. This  plan  is  seldom  followed  because  the  owner  is  usually  not 
willing  to  give  up  the  use  of  his  pasture  even  temporarily.  The  in- 
direct plan  consists  in  permitting  the  cattle  and  other  animals  to 
continue  on  the  infested  i:)asture  and  treating  them  at  regidar  inter- 
vals with  agents  destructive  to  ticks,  thus  preventing  engorged 
females  from  dropping  and  reinfesting  the  pasture.  All  the  seed 
ticks  on  the  j^asture,  or  those  which  hatch  from  eggs  laid  by  females 
already  there,  will  die  eventually.  Those  that  get  on  the  cattle  from 
time  to  time  will  be  destroyed  by  the  treatment,  while  those  which 
fail  to  find  a  h^st  will  starve  to  death  in  the  joasture. 


Ticks  upon  cattle  may  be  destroyed  by  using  a  tick-destroying 
agent,  such  as  arsenic.  The  dipping  vat  is  the  best  and  cheapest 
means  of  applying  the  remedy.  The  great  advantage  of  dipping 
over  spraying  and  applying  remedies  by  hand  lies  in  the  fact  that 
thoroughness  of  the  treatment  is  practically  assured. 

PROCEDURE  IN  DIPPING.     " 

When  eradication  is  undertaken,  all  the  cattle,  and  also  the  horses 
and  mules  if  they  harbor  ticks,  are  treated  regularl}'  every  two 
weeks  during  the  part  of  the  year  that  the  temperature  is  favorable 
to  treatment,  until  the  ticks  have  disappeared.  The  purpose  of  the 
treatment  is  to  destroy  all  ticks  that  get  on  the  animals  before  they 
have  had  a  chance  to  mature  and  drop,  thus  preventing  them  from 
reinfesting  the  pasture,  farm,  or  range.  If  the  treatment  used  weri> 
absolutely  effective  in  destroying  each  and  every  tick  on  the  animals 
treated  there  would  be  no  renewal  of  the  infestation  after  the  treat- 
ment is  begun.  The  cattle  would  act  simply  as  collectors  of  ticks 
which  would  be  destroyed  regularly  by  the  treatment  applied  every, 
two  weeks.  It  is  probable,  however,  that  in  most  instances,  either  be- 
cause of  the  lack  of  efficiency  of  the  dip  or  imperfect  application,  or 
because  of  failure  to  dip  all  cattle  systematically,  some  tides  escape 
treatment  and  reproduce,  thus  prolonging  the  time  that  otherwise 
w^ould  be  required  for  eradication. 

If  ticks  apparently  disappear  from  the  cattle  after  they  have  been 
under  treatment  foi-  some  time,  the  dipping  shouhl  not  be  discon- 
tinued until  a  number  of  careful  inspections  show  that  tlie  cattli>  arc 


Cattle-Fever  Ticks.  13 

-free  of  ticks.  If  ticks  continue  on  cattle  until  cold  weather  and  then 
finally  disappear  it  should  be  borne  in  mind  that  in  all  probability 
eradication  has  not  been  accomplished  and  that  there  may  be  en- 
gorged females,  unhatched  eggs,  and  inactive  seed  ticks  on  the  farm 
or  range,  and  that  even  if  the  cattle  should  remain  free  of  ticks  dur- 
ing the  winter  they  may  become  reinfested  the  following  spring.  In 
any  case  in  which  ticks  disappear  from  the  cattle  and  treatment  is 
discontinued,  the  cattle  should  be  watched  very  carefully  for  ticks 
until  ample  time  has  elapsed  to  leave  no  doubt  that  eradication  has 
been  accomplished. 

As  a  general  rule  it  has  been  found  that  if  dipping  is  begun  in 
March  and  systematically  and  thoroughly  done,  all  cattle  being 
dipped  every  14  days  until  November,  complete  eradication  will  be  se- 
cured. In  dipping,  each  animal  should  be  completely  covered  by  the 
dip.  To  preA'ent  any  animals  from  going  through  the  vat  without  be- 
coming wet  all  over,  a  man,  provided  with  a  forked  stick,  should  be 
stationed  at  the  middle  of  the  vat  to  shove  under  those  that  have  not 
been  completely  submerged. 

Dipping  is  the  only  really  satisfactory  method  of  treating  animals 
for  ticks.  In  cases  of  emergency,  however,  or  where  there  are  not 
cattle  enough  within  a  radius  of  several  miles  to  warrant  the  con- 
struction of  a  vat  in  which  all  the  cattle  of  the  community  may  be 
dipped,  spraying  may  be  advisable.  In  spraying  animals  the  work 
should  be  done  with  great  thoroughness  and  every  portion  of  the 
body  treated.  An  animal  can  not  be  sprayed  properly  unless  it  is 
tied  or  otherwise  held,  nor  can  good  results  be  obtained  unless  the 
hair  and  skin  are  thoroughly  wetted. 

RULE  FOR  CALCULATING  THE  CAPACITY  OF  A  VAT. 

The  capacity  of  the  vat  is  obtained  usually  in  the  following  manner : 
Multiply  the  average  length  by  the  average  W'idth  in  inches,  then 
multiply  the  product  by  the  depth;  this  will  give  the  approximate 
number  of  cubic  inches  of  space  to  be  filled  with  dip.  Divide  this  by 
231  (the  number  of  cubic  inches  in  a  gallon),  and  the  result  will  be 
the  number  of  gallons  of  dip  required  to  charge  the  vat. 

To  obtain  the  average  length,  add  the  length  at  the  bottom  to  the 
length  at  the  top  (that  is,  at  the  line  to  which  the  vat  is  to  be  filled), 
and  divide  the  sum  by  2.  Obtain  the  average  width  in  the  same  man- 
ner. The  depth  should  be  taken  at  the  center  of  the  vat,  and  should 
be  from  bottom  to  dip  line  only  and  not  to  the  top  of  the  vat.  Like- 
wise, in  determining  the  length  and  width,  measure  only  the  space  to 
be  filled  with  liquid  and  not  above  that  line.  Gauges  or  rods  should  be 
prepared  and  marked  to  show  the  number  of  gallons  at  various 
depths  in  the  vat. 


14         '  Farmers'  Bulletin  1057. 

SPECIFICATIONS    FOR  THE   CONSTRUCTION    OF   A    CONCRETE  VAT. 

Site. — The  site  selected  for  the  vat  should  be  dry  and  of  sufficient 
size  to  pennit  the  construction  of  the  chute,  the  dripping  pen,  and  at 
least  two  additional  pens — one  for  holding  the  cattle  prior  to  dipping 
and  the  other  for  retaining  them,  after  dipping,  until  sufficiently 
dried. 

Excavation. — The  excavation  should  be  made  1  foot  wider  and  1 
foot  longer  than  the  inside  dimensions  of  the  vat  and  should  conform 
to  its  shape.  The  inside  dimensions  of  the  vat  are  shown  on  the 
drawings  (figure  5)  and  are  as  follows:  Length  at  top  of  vat,  26 
feet;  bottom,  12  feet;  width  at  top,  3  feet;  at  bottom,  li  feet;  depth, 
7  feet. 

The  sides  and  bottoms  of  the  excavation  should  be  firm  and  solid, 
as  they  are  to  serve  for  the  outside  forms  in  casting  the  concrete.  If 
it  is  necessary  to  do  any  filling  in  order  to  conform  to  the  shape  of 
the  vat,  the  filling  should  be  puddled  and  thoroughly  rammed  until 
solid.    The  stability  of  the  concrete  depends  on  the  foundation. 

Forms  and  fences. — The  wooden  forms  should  be  constructed  of 
1-inch  boards  and  2  by  4  inch  braces,  the  boards  being  nailed  to  the 
outside  face  of  the  braces,  as  shown  in  the  drawings.  The  sides  and 
end  walls  should  be  built  8  inches  higher  than  the  surface  of  tlie 
ground,  which  should  be  level.  Any  suitable  lumber  may  be  used  for 
the  forms  and  fences.    Saplings  may  be  used  for  posts. 

Concrete. — The  concrete  should  be  made  of  (by  measure)  1  part  of 
cement,  2|^  parts  of  sand,  and  5  of  broken  rock  or  gravel.  The  cement 
should  be  of  standard  brand  of  Portland,  the  sand  clean  and  coarse, 
and  the  broken  rock  from  about  |-inch  pieces  to  those  not  larger  tlian 
will  pass  in  every  direction  through  a  1-inch  ring.  A  vat  according 
to  the  plan  (figure  5)  will  require  about  40  sacks  of  cement,  5  yards 
of  sand,  and  10  yards  of  gravel. 

A  26-foot  vat  is  used  extensively  for  eradication  purposes  with 
satisfactory  results.  If  it  is  desired,  however,  to  lengthen  the  body 
of  the  vat  on  account  of  large  numbers  of  cattle  to  be  treated,  the  fol- 
lowing quantities  of  concrete  material  should  be  added  for  each  lineal 
or  running  foot — cement,  1^  sacks;  sand,  0.12  yard;  stone,  0.24  yard. 

The  sand  is  measured  out  first  and  the  cement  emptied  on  to]),  and 
the  two  materials  thoroughly  mixed,  dry.  In  the  meantime  the  stone 
may  be  measured  out  and  thorougldy  drenched  with  water.  The 
cement-sand  mixture  is  mixed  with  water  and  the  resulting  mortar 
then  combined  with  the  stone.  The  stone  should  be  slioveled  on  tlie 
mortar,  previously  spread  out  in  a  thin  layer.  Mixing  should  con- 
tinue until  the  stone  is  thoroughly  coated  with  mortar,  more  water 
being  added  during  the  mixing  process  if  necessary. 


Cattle-Fever  Ticks. 


15 


16  Farmers'  Bulletin  1057. 

Laylny. — Before  hn'ing  the  concrete  the  molds  should  be  set  and 
thoroughly  braced  into  place.  The  side  forms  may  be  suspended  iii 
the  excavation  with  their  lower  edges  6  inches  from  the  bottom. 
They  are  held  in  place  by  crosspieces  nailed  to  the  uprights  and  of 
sufficieijt  length  to  rest  on  supports  placed  several  feet  from  the  edges 
of  the  excavation.  The  concrete  for  the  bottom  and  incline  is  de- 
posited first,  the  mixture  being  of  a  consistence  that  water  will  flush 
to  the  surface  on  ramming.  The  mixtures  for  the  sides  and  end 
should  be  very  wet  and  thoroughly  puddled  into  place.  The  con- 
sistence of  the  concrete  for  the  side  walls  should  be  such  that  it  will 
run  off  the  shovel  unless  handled  quickly. 

The  laying  of  the  concrete  should  be  done,  if  possible,  in  one 
operation,  so  there  will  be  no  joints  between  new  and  old  work.  If 
it  becomes  necessary  to  do  the  concrete  work  on  two  or  more  days 
the  surface  to  receive  the  new  concrete  should  be  washed  clean  and 
coated  w^ith  a  grout  of  pure  Portland  cement  and  water  mixed  to 
the  consistence  of  cream.  The  new  concrete  should  be  placed  before 
the  grout  has  set.  Extreme  care  must  be  taken  to  prevent  dirt  from 
falling  on  top  of  the  fresh  concrete. 

The  forms  should  not  be  removed  until  the  concrete  is  set,  which 
in  moderate  weather  takes  place  in  about  24  hours.  Wet  down  the 
concrete  about  twice  in  24  hours  until  the  forms  are  removed.  Tn 
damj),  cold  weather  at  least  48  hours  should  be  allowed  before  re- 
moving the  forms.  It  is  advisable,  especially  in  water-soaked 
ground,  to  allow  the  forms  to  remain  in  place  for  one  week  before 
removal. 

Surfacing  or  pnishing  coat. — Dampen  the  walls  before  applying 
the  finishing  coat.  Cover  the  entire  inside  surface  of  walls  and 
floor  with  a  coating  of  cement  and  sand,  mixed  half-and-half,  and 
with  water  enough  to  make  it  "quaky."  Place  a  small  quantity  of 
the  mixture  on  a  float;  beginning  at  the  bottom  of  the  wall  as  near 
the  floor  as  possible,  make  one  stroke  upward;  take  up  another  float 
of  the  cement-sand  mixture,  overlap  the  ending  of  the  last  float  and 
make  another  upward  stroke.  Repeat  until  walls  are  completed. 
Do  not  try  to  float  the  walls  too  smooth.  Finish  with  cement  and 
water  mixed  to  thickness  of  cream  and  applied  with  a  kalsomine  or 
whitewash  brush. 

Exit  incline. — The  exit  incline,  as  shown  in  the  plans  (figure  5), 
is  not  so  steep  as  to  require  a  cleated  false  bottom.  The  surface, 
however,  should  be  finished  very  roughly  to  permit  the  animals  to 
maintain  a  secure  foothold. 

Slide. — The  slide  for  dry  or  range  cattle  may  be  built  only  2  feet 
long  with  a  drop  of  2  feet.  Yor  dairy  cows,  however,  it  is  advisable 
to  have  a  slide  4  feet  long,  ihat  is,  long  enougli  for  the  cow  to  stand 


Cattle-Fever  Ticks.  17 

on,  with  a  drop  of  2|  or  3  feet  so  that  the  arsenical  bath  will  cover 
the  edge  of  the  slide  at  least  a  foot  in  depth.  This  kind  of  slide 
for  dairy  cows  prevents  bruising  the  udders. 

Slides  should  be  finished  veiy  smooth  by  much  floating  of  the 
concrete  and  finishing  with  a  mixture  of  equal  parts  of  cement  and 
fine  sand. 

Cover. — The  vat  should  be  so  inclosed  or  covered  as  to  keep  chil- 
dren or  small  animals  from  entering  or  falling  in. 

Dripping  chute  and  chute  leading  to  the  vat. — The  dripping  chute, 
which  is  regarded  as  more  satisfactory  than  a  dripping  pen,  is  built 
at  the  head  of  the  exit  incline  in  line  with  the  vat.  It  should  be 
about  30  inches  wide.  The  length  will  depend  on  the  number  of 
cattle  to  be  accommodated  at  one  time.  From  4  to  5  feet  are  allowed 
for  each  animal,  and  a  length  of  from  20  to  40  feet  is  considered  a 
convenient  size  for  small  herds.  The  floor  should  be  made  of  con- 
crete, at  least  18  inches  wide,  sloping  toward  the  vat  so  that  the 
dripping  from  the  cattle  will  flow  back  into  the  vat  through  the  open- 
ing provided.  The  floor  at  the  sides  of  the  chute  is  raised  about  2 
inches  in  the  form  of  a  curb  to  keep  the  dip  from  ninning  off. 

The  chute  leading  to  the  vat  should  be  not  more  than  30  inches 
wide  and  20  feet  long  and  it  is  desirable  to  have  the  receiving  pen 
and  retaining  chute  large  enough  to  accommodate  the  animals  to  be 
dipped. 

PASTURE  ROTATION. 
TIME   REQUIRED   TO   KILL  TICKS   BY   STARVATION. 

The  time  necessary  for  ticks  to  die  out  on  a  pasture  after  removal 
of  the  cattle  is  of  importance  with  reference  not  onl}'  to  methods  of 
eradication  by  rotation  but  to  methods  of  eradication  b}"  dipping. 
AVhen  systematic  dipping  is  begun  and  further  infection  of  the  pasture 
is  stopped  by  killing  all  ticks  that  get  on  the  cattle,  the  period  during 
which  the  dipping  must  be  continued  in  order  to  secure  eradication 
is  prmiarily  dependent  upon  the  length  of  life  of  the  seed  ticks 
already  on  the  pasture  and  of  those  that  hatch  out  from  eggs  laid  by 
ticks  that  dropped  before  dipping  was  begun. 

The  time  required  for  the  ticks  to  die  out  after  all  animals  have 
been  removed  from  infested  fields  and  pastures  varies  considerably, 
depending  principally  on  the  climate  and  the  weather.  The  dates 
when  pastures  will  be  free  of  ticks  after  all  cattle  have  been  removed 
are  given  in  the  following  table : 


18 


Farmers'  Bulletin  1057. 


\ 


Table  1. —  Time  required  to  free  pastures  from  ticls  hy  starvation. 

BASED  ON  DATA  OBTAINED  AT  DALLAS,  TEX.,  AND  AUBUIIN,  ALA. 


Date  of  removal  of  all  animals  from 
pasture. 


Date 
when 
pasture 
will  be 
free 
from 
ticks. 


Date  of  removal  of  all  animals  from 
pasture. 


Date 
when 
pasture 
will  be 
free 
from 
ttcks. 


Julyl 

Aug.  1 

Sept.  1 

Oct.  1  to  Nov. 
Dec.l 


Mar.  1 
May  1 
July  1 
Aug.  1 
Aug.  15 


Dec.  15  to  Mar.  I.j,  inclusive. 

Apr.  1 

Apr.  15 

May  1  to  Jime  15,  inclusive. . 


.  Sept.  1 
.  Sept.  15 
.  Oct.  15 
.1  Nov.    1 


BASED  ON  DATA  OBTAINED  AT  KXOXVILLE,  TENN. 


Jan. 1 

Feb.  1  to  Mar.  15. 

Apr.ltol5 

Mayl 

May  15  to  June  1 . 


Aug. 

1 

Nov. 

15 

Jan. 

1 

Jan. 

15 

l-'eb. 

15 

June  15 

Julyl 

July  15 

Aug.  1  to  15 

Sept.  1  to  Oct. 


May  1 
June  15 
July  1 
July  15 
Sept.  15 


The  first  j)art  of  the  table  is  based  on  investigations  by  Hunter 
and  Hooker^  at  Dallas,  Tex.,  and  by  Graybill  at  Auburn,  Ala.,  under 
cooperation  between  the  Bureau  of  Animal  Industry  and  the  veteri- 
nary department  of  the  Alabama  Polytechnic  Institute.-  All  the 
IDeriods  obtained  by  Newell  and  Dougherty  (190G)^  in  work  carried  on 
at  Baton  Rouge,  La.,  which  is  much  further  south,  are  shorter.  The 
periods  given  in  the  table  should  be  found  ample  for  all  places 
no  further  north  than  Dallas,  Tex.,  or  Auburn,  Ala. 

In  general,  moisture  and  cold  prolong,  while  dryness  and  heat 
shorten,  the  duration  of  the  period  that  ticks  will  live  on  a  pasture. 
If  some  portions  of  the  same  pasture  differ  with  regard  to  tem- 
perature and  moisture,  as  frequently  happens,  some  parts  become 
free  of  ticks  before  others  do.  Other  things  being  equal,  high,  dry, 
unshaded  land  becomes  tick-free  sooner  than  low,  damp,  .shady  land. 
Land,  however,  that  is  excessively  moist  and  extremely  shady,  as 
along  some  river  bottoms,  is  not  likely  to  be  a  favorable  breeding 
place  for  the  cattle  ticks,  and  lowlands  subject  to  more  or  less  regu- 
lar overflows,  as  a  rule  are  only  lightly  infested,  if  at  all. 

The  time  required  for  freeing  pastures  in  the  southern  part  of  the 
infested  area  may  be  considerably  less  in  many  localities  than  that 
indicated  in  the  fii-st  part  of  Table  1,  yet  the  safest  plan  is  to  follow 
the  table  in  most  localities  in  the  South.  There  is  little  doubt  that 
in  most  regions  in  the  northern  half  of  the  infested  area  the  jieriods 

'  Bulletin  72,  Bureau  of  lOntoniolofry,  TT.  S.  Department  of  Agriculture. 
■'Bulletin  l.'.O,  Bureau  of  Animal  Industry,  11.  S.  Department  of  Agriculture. 
»  Circular   10,  State  Crop  Pest  Commission   of  Louisiana. 


Cattle-Fever  Ticks.  19 

are  longer.  Cotton  ^  obtained  at  Knoxville,  Tenn.,  during  the  years 
from  1907  to  1909,  inclusive,  the  periods  given  in  the  lower  part  of 
Table  1. 

According  to  the  experiments  conducted  by  Cotton,  the  normal 
duration  of  an  infestation  may  be  considerably  shortened  or  even 
suddenly  brought  to  an  end  in  infested  pastures  and  fields  by  the 
occurrence  of  exceptionally  cold  weather.  He  found  that  a  certain 
per  cent  of  engorged  females  are  destroyed  by  a  temperature  of 
23°  F.,  that  all  engorged  females  are  destroyed  by  a  temperature  of 
14°  F.  when  not  provided  with  a  protective  covering,  and  that  ticks 
provided  with  a  covering  of  dry  chaff  were  able  to  survive  a  tem- 
perature of  12°  F.,  but  if  the  covering  is  wet  they  are  killed  as 
readily  as  when  unprotected.  It  was  found  also  that  ticks  that  have 
deposited  some  eggs  are  much  more  readily  destroyed  than  those 
that  have  not  done  so.  In  addition  it  was  demonstrated  that  all 
unprotected  eggs  and  all  seed  ticks  are  destroyed  at  temperatures 
of  4°  F.  and  2°  F.,  respectively,  but  that  eggs  protected  by  dry  litter 
can  endure  a  much  colder  temperature.  It  is  thus  seen  that  the  in- 
festation of  fields  may  be  greatly  reduced  during  cold  spells  and,  if 
the  temperature  falls  to  about  zero,  may  be  entirely  destroyed.  In 
case  the  temperature  falls  only  to  a  point  at  which  all  the  females 
are  destroyed,  the  only  result  accomplished  will  be  a  shortening  of 
the  period  of  infestation. 

It  would  be  well  for  stock  owners,  in  eradicating  ticks,  to  take 
advantage,  so  far  as  practicable,  of  all  zero  weather.  It  should  be  re- 
membered, however,  that  cattle  even  during  the  coldest  weather  are 
likely  to  harbor  ticks  which  will  be  unaffected  by  the  low  tempera- 
ture. The  ticks  when  they  drop  will  reinf est  the  place ;  consequently, 
when  a  spell  of  zero,  weather  occurs,  if  the  cattle  are  not  on  the  fields, 
pastures,  or  ranges  they  should  not  be  returned  to  them  until  freed 
of  ticks.  If  on  pasture  they  should  be  removed  at  once  and  not  re- 
turned until  made  free  of  ticks  by  one  of  the  methods  suggested  in 
this  bulletin. 

TIME    REQUIRED    TO    FREE    CATTLE    OF   TICKS    ON    UNINFESTED    FIELDS. 

Although  the  method  is  not  often  used,  it  is  nevertheless  possible 
to  free  cattle  of  ticks  by  placing  them  on  a  series  of  uninfested  fields. 
This  plan  is  based  on  the  fact  that  the  female  tick  must  drop  from 
the  host  to  the  ground  before  eggs  can  be  laid  and  before  young  ticks 
will  develop. 

The  shortest  time  in  which  seed  ticks  appear  after  engorged  females 
have  been  dropped  is  20  days.  Consequently,  cattle  placed  on  a  tick- 
free  field  during  the  warmer  part  of  the  year  are  not  in  danger  of 

^  Bulletin  94,  Agricultural  Experiment  Station  of  the  University  of  Tennessee. 


20 


Farmers'  Bulletin  1057. 


becoming  infested  again  with  young  ticks  until  :iO  daj-s  liave  elapsed. 
The  time  required  for  all  the  ticks  to  drop  after  cattle  have  been 
placed  on  uninfested  land  varies  "with  the  temperature,  being  much 
longer  in  winter  than  in  summer.  Beginning  at  various  times  of  the 
year,  the  time  required  is  given  in  Table  2. 

Table  2. — Time  required  for  all  tichs  to  drop  from  cattle  placed  on  tick-free  land. 


When  tickv  cattle  are  placed  on 
tick-free  land  during— 

AU  ticks  will 

have  dropped 

in— 

■V\Tien  ticky  cattle  are  placed  on 
tick-free  land  during— 

All  ticks  Will 

have  dropped 

in— 

August 

Six  weeks. 

March... 

?ev"n  weeks. 

Do. 
Eight  weeks. 
Nine  weeks. 
Ten  weeks. 
Seven  weeks. 

April 

Six  weeks. 

May 

Do. 

Do. 

.Tanuary 

July 

Five  weeks. 

February 

Freeing  cattle  of  ticks  by  rotation  on  tick-free  land. — The  plan  of 
freeing  cattle  of  ticks  by  changing  them  from  one  lot  or  field  to 
another  is  as  follows :  Beginning  at  any  time  of  the  year  from  March 
to  September,  inclusive,  in  the  southern  half  of  the  infested  area,  the 
cattle  are  removed  from  the  tick-infest'^d  pasture  they  have  been 
occupying  to  a  tick- free  lot  or  field  and  left  there  for  not  more  than 
20  daj'S.  During  that  time  a  considerable  number  of  ticks  will  drop. 
In  order  to  prevent  the  cattle  from  becoming  reinfested  (by  seed 
ticks  resulting  from  eggs  laid  by  females  that  have  dropped),  the 
herd  is  then  changed  to  a  second  tick-free  inclosure  for  20  days 
longer,  and  if  they  are  not  free  of  ticks  by  that  time,  they  are  placed 
in  a  third  tick-free  inclosure  for  20  days  more.  Should  the  two 
changes  at  intervals  of  20  days  have  been  made,  60  days  will  have 
elapsed,  which,  during  the  time  of  year  indicated,  is  ample  time  for 
all  ticks  to  have  dropped,  and  the  animals  are  ready  to  be  placed  on 
a  tick-free  pasture  or  field  without  danger  of  becoming  reinfested. 
The  periods  to  free  cattle  (given  in  the  table  above)  are  believed  to 
be  ample.  It  is  a  wise  precaution,  however,  to  examine  the  cattle 
carefull}''  for  ticks  before  placing  them  in  the  uninfested  field  they 
are  to  occupy. 

From  October  to  February,  inclusive,  the  time  required  for  seed 
ticks  to  appear  after  females  have  dropped  is  much  longer  than  the 
time  necessary  for  all  the  ticks  to  drop  from  cattle.  Consequently,  if 
it  is  desired,  the  herd  maj^  be  left  on  the  same  field  for  the  recinirod 
length  of  time  without  danger  of  reinfestation. 

Table  3  gives  the  approximate  dates  when  ticlcj-  cattle  are  in 
danger  of  reinfestation  when  jilaced  on  tick-free  land  at  various 
times  of  the  year.  The  first  section  applies  to  most  localities  in  the 
southern  half  of  the  infested  region,  and  the  second  section  to 
localities  having  temperature  conditions  about  the  same  as  Knoxville, 
Tenn. 


Cattle-Fever  Ticks. 


21 


Table  8. — Date  on  tcMch  seed  ticks  will  appear  after  tiektj  cattle  have  been 
placed  on  tick-free  land. 

BASED   ON    DATA    OBTAINED    AT    BATON    EOUGE,    LA.,    AUBURN,    ALA.,    AND    DALLAS,    TEX. 


Date  cattle  placed  on  tick-fre 
pastures. 


Jan.  1  to  Feb.  4,  inclusive. 

Mar.3 

Apr.  15 

May  1 

Jime5 

Julyl 

Aug.  5 

Sept.  1 

Oct.  1 

Nov.  1  to  Dec.  15,  inclusive 


Date  seed 

ticks  will 
appear. 


Apr.  24 
May     3 

May  20 
June  5 
Juno  28 
July  25 
Aug.  30 
Oct.  7 
Feb.  25 
Mar.     3 


BASED    ON    DATA    OBTAINED    AT    KNOXVILLE,    TENN. 


Jan.  11  to  Mar.  4,  inclusi\ 
Apr. 


Apr.  1.. 
M^ylo. 
June  12. 
Julys.. 
Aug.  6. . 
Sept.  4. 
Oct.  2.. 


Mav 

29 

June 

3 

Jime 

20 

July 

19 

Aug. 

2 

Sept. 

6 

K 

14 
20 

ARSENICAL  DIPS. 

PROPERTIES    OF    SUBSTANCES    USED    IN    MAKING    ARSENICAL    DIPS. 

The  successful  preparation  of  an  arsenical  dip  calls  for  some 
knowledge  of  the  properties  of  the  raw  materials. 

WHITE   ARSENIC. 

White  arsenic  {arsenic  frioxid,  arsenious  or  arsenous  oxid  or  acid?) 
must  be  purchased  in  the  form  of  a  fine  powder  and  under  a  guaranty 
of  98  or  90  per  cent  purity.  Water,  even  when  boiling-,  dissolves  it 
only  slowly,  but  by  the  use  of  certain  other  chemicals  it  may  readily 
and  abundantly  be  brought  into  solution. 

One  must  never  forget  that  white  arsenic  is  a  violent  poison  to 
man  and  animals.  So  are  the  concentrated  dij)S  prepared  from  it. 
The  precautions  necessary  for  safety  will  be  discussed  under  a 
separate  section,  and  any  person  who  has  anything  whatever  to  do 
with  arsenical  dips  is  advised  to  read  it  often  enough  to  keep  the 
points  fresh  in  mind. 

CAUSTIC   SODA. 

Caustic  soda  {sodmm  hydroxid)  ^  on  account  of  its  wide  range  of 
application  by  chemists,  pharmacists,  and  manufacturing  indu.stries, 
occurs  commercially  in  a  number  of  different  forms,  as  powder, 
sticks,  solid  masses,  or  broken  fragments;  in  color  it  ranges  from 
pure  white  to  grayish  or  brownish  tints.  For  the  use  of  chemists  and 
pharmacists  it  is  put  up  in  glass  bottles;  for  industrial  purposes  it 
is  supplied  in  various-sized  cans  or  drums  of  thin  sheet  iron.  The 
latter  is  the  variety  that  should  be  purchased  for  making  dip.    The 


22  Farmers'  Bulletin  1057. 

5  or  10-pound  can  is  the  best  size  to  buy  for  home  use;  larger  con- 
sumers probably  can  handle  the  material  in  larger  drums  conven- 
iently and  of  course  more  economically.  The  j^urchaser  must  make 
sure  that  the  contents  of  the  drum  he  contemplates  buying  are  in 
fragmentary  form,  for  some  caustic  soda  is  run  into  drums  in  a 
melted  condition  and  on  cooling  forms  a  single  solid  cake,  which  is 
not  adapted  for  the  present  purpose.  It  always  should  be  purchased 
under  a  guaranty  of  not  less  than  85  per  cent  actual  caustic  soda. 

Caustic  soda  is  an  intensely  active  and  powerful  substance.  AYlien 
exposed  to  the  air  it  stronglj^  attracts  moisture,  increasing  in  weight 
and  becoming  pasty,  while  at  the  same  time  it  becomes  contaminated 
with  sodium  carbonate  through  absorption  of  carbon  dioxid.  Hence 
it  always  must  be  purchased  in  original  containers,  never  in  bulk; 
the  container  must  not  be  opened  until  just  before  the  material  is 
to  be  used;  the  substance  must  not  be  allowed  to  stand  exposed  to 
the  air,  and  if  any  is  left  over  which  is  to  be  kept  for  subsequent 
use  it  must  be  immediately  transferred  to  a  tin  pail  provided  with  a 
tight-fitting  cover. 

Owing  to  the  intense  chemical  activity  of  caustic  soda  it  is  ex- 
tremely corrosive  in  its  effect  upon  skin  or  clothes,  and  upon  the 
lungs  if  its  dust  is  inhaled.  Therefore  it  is  necessary  to  handle  it 
gently  to  avoid  the  raising  of  dust  and  to  wash  off  at  once  with  water 
any  which  may  touch  the  skin  or  clothing. 


Lye  designates  a  grade  of  caustic  soda  put  up  primarily  for  domes- 
tic use,  such  as  making  soap  from  waste  grease  and  for  general 
cleansing.  It  is  sometimes  of  very  inferior  quality.  If  a  guaranty 
regarding  its  purity  can  be  obtained,  it  may  be  used  for  dip  making, 
in  case  of  necessity,  in  the  same  proj^ortions  as  caustic  soda. 

SODIUM   CARBONATE. 

Sodium  carbonate  is  sold  in  a  number  of  forrtis  which  differ 
greatly  in  strength,  that  is,  in  the  proportion  of  actual  sodium  car- 
bonate they  contain.  Consequently  the  cheapest  in  cost  per  pound 
may  not  be  the  most  economical  to  use.  Soda  mh  is  the  strongest,  but 
is  not  recommended  for  the  home  preparation  of  dips.  It  is  of  un- 
certain strength  when  purchased  and  becomes  weaker  on  exposure  to 
air,  while  in  contact  with  water  it  lumj)s  badly  and  dissolves  slowly, 
Sal  soda  is  the  weakest  and  probably  the  least  economical  form,  but 
because  it  is  so  well  known  and  so  easily  obtained  it  has  been  the 
most  generally  used  form  of  sodium  carbonate  for  homemade  dips. 
Its  relative  weakness  is  due  to  the  fact  that  almost  two-thirds  of  it 
is  water,  combined  as  "  water  of  crystallization."  "When  fresh  it  con- 
sists of  large,  nearly  transparent  crystals,  but  on  exposure  to  air  it 
tends  to  fall  to  a  white  powder.  This  change  is  simply  due  to  the 
evaporation  of  the  water  of  crystallization,  and  consequently  the 


Cattle-Fever  Ticks.  23 

material  becomes  stronger,  almost  approaching  nwnohrjdrated  sodiwm 
carhonate.  This  latter  substance  is  a  coarse,  granular  powder,  con- 
taining only  about  one-seventh  of  its  weight  of  water  of  crystalliza- 
tion, and  is  very  little  affected  by  exposure  to  air.  Sesquicarhonate  of 
soda  is  still  another  form  which  is  stronger  than  sal  soda,  contain- 
ing less  than  one-third  of  its  weight  of  substances  not  actual  sodium 
carbonate.    It  is  likewise  little  affected  by  air. 

Both  monohydrated  carbonate  and  sesquicarhonate  dissolve  readily 
and  can  replace  sal  soda  to  excellent  advantage  provided  their  com- 
position is  guaranteed  by  a  reliable  firm.  In  calculating  formulas 
and  costs  it  may  be  assumed  that  10  pounds  of  sal  soda  can  be  re- 
placed by  4^  pounds  of  the  monohydrate  or  5  pounds  of  the  sesqui- 
carhonate. 

PINE  TAR. 

Pine  tar  when  fresh  is  semiliquid,  but  with  age  becomes  granular 
and  nearly  solid,  in  which  condition  it  is  of  less  value.  Mixed  with 
it  is  usually  more  or  less  water  of  decidedly  acid  properties  (pyro- 
ligneous  acid),  which  on  standing  tends  to  float  on  the  surface  and 
should  be  dipped  or  poured  off  before  the  tar  is  used. 

Tar  is  heavier  than  water  and  when  stirred  with  it  usually  forms 
a  very  poor  mixture  from  which  most  of  the  tar  rapidly  settles  out, 
but  when  the  water  is  of  just  the  right  temperature  and  somewhat 
alkaline  a  fairly  stable  suspension  generally  may  be  obtained.  Wlien 
previously  treated  with  caustic  soda  sufficient  to  combine  with  a  con- 
siderable proportion  of  the  tar  acids,  or  when  blended  with  soap,  the 
tar  easily  mixes  with  water  and  then  forms  a  good  and  permanent 
emulsion. 

THE  GENERAL  COMPOSITION  OF  DIPS. 

All  arsenical  cattle  dips  contain  arsenious  oxid  as  the  active  tick- 
killing  agent.  But  since  straight  arsenious  oxid — that  is,  white  ar- 
senic— is  so  slowly  soluble  in  water,  some  chemical  agent  such  as 
sodium  carbonate  or  hyclroxid  is  necessary  to  bring  it  into  solution. 
In  this  way  the  white  arsenic  is  changed  to  sodium  arsenite.  If  cer- 
tain manufacturing  difficulties  can  be  overcome  it  is  possible  that 
sodium  arsenite  of  reliable  composition  may  appear  later  on  the 
market.  Such  a  material  could  be  dissolved  directly  in  water  and  the 
trouble  of  making  the  compound  from  white  arsenic  and  caustic  soda 
would  be  avoided. 

But  a  plain  water  solution  of  sodium  arsenite,  however  obtained, 
does  not  make  an  entirely  satisfactory  dip.  Better  results  follow 
when  pine  tar  is  added.  Possibly  the  pine  tar  increases  the  wetting 
or  spreading  power  of  the  bath,  which  naturally  results  in  better 
penetration  and  effectiveness  against  ticks  and  less  risk  of  blistering 
cattle.  It  is  probable  that  the  pine  tar  also  makes  the  sodium  arsenite 
adhere  better,  so  that  it  will  less  readily  wash  off  in  rain,  or  dust  off 
in  dry  weather.    Perhaps  it  is  distasteful  to  seed  ticks  so  that  they 


24  Farmers'  Bulletin  i057. 

are  less  liable  to  attach  to  cattle  after  dipping.  Probably,  too,  cattle 
will  be  less  inclined  to  drink  the  bath  while  going  through  the  vat. 

Proprietary  arsenical  cattle  dips  appear  now  to  have  passed  the 
experimental  stage  and  to  have  become  established  as  reliable  and 
"aseful  products.  At  any  rate  this  can  be  said  of  the  brands  which 
have  received  permission  for  use  in  oflScial  dipping  in  place  of  the 
homemade  dip.  The  formulas  and  standard  samples  of  all  such  brands 
are  in  possession  of  the  Bureau  of  Animal  Industry  and  the  manu- 
facturers are  required  to  guarantee  that  their  products  as  pk«:-ed  on 
the  market  will  be  kept  up  to  standard  and  that  all  requirements  of 
the  bureau  will  be  observed.  Like  the  homemade  dip  they  all  contain 
sodium  arsenite  as  the  active  tick-killing  agent.  They  do  not  all 
contain  pine  tar,  because  that  substance  is  difficult  to  blend  into  a 
highl}^  concentrated  product,  but  they  all  contain  some  other  sub- 
stance or  mixture  of  substances  of  such  character  and  in  such  quantity 
as  field  trials  have  proved  will  produce  the  same  effects. 

They  are  not  regarded  as  any  more  effective  or  any  milder  on  the 
cattle  than  properly  prepared  homemade  dips.  None  the  less  they 
are  undoubtedly  safer  for  general  use  because  they  offer  decidedly 
fewer  opportunities  for  making  mistakes  in  the  quantities  used  or  in 
the  operations  gone  through  and  also  fewer  chances  for  accidental 
poisoning  or  other  injury  from  the  handling  of  powerful  chemicals. 
A^Tiether  their  higher  cost  is  sufficiently  outweighed  by  these  con- 
siderations is  necessarily  a  matter  for  individual  decision. 

MAKING  THE  S-B   DIP.' 

Homemade  dips  usually  are  made  after  the  "  S-B  "  formula. 
This  calls  for  two  stock  solutions,  arsenic  stock  and  tar  stock, 
which  must  not  be  mixed  except  in  the  diluted  dipping  bath. 

1  Abbreviated  from  "  self-boiled,"  because  sufficient  heat  to  prepare  the  dip  is  generated 
by  chemical  ad  ion  between  the  raw  materials.  The  field  men  of  tlie  bureau  do  not  n^roe 
on  the  best  metliod  of  mixing;.  The  truth  is  that  several  modifications  trive  pood  results 
in  the  hands  of  experienced  men  and  each  man  naturally  prefers  the  one  with  which  he 
is  most  familiar.  The  method  of  mixing  here  given  ia  the  original  method  puhlishod  in 
Farmers'  Bulletin  60.'?,  and,  all  things  considered,  appears  to  be  somewhat  the  safest  to 
recommend  for  general  use,  particularly  to  those  who  must  depend  entirely  on  printed 
instructions.  lUit  a  modification  devised  by  Dr.  Harry  Grafke,  of  the  Bureau  of  Animal 
Industry,  may  be  of  interest.  lie  says:  "  In  a  fl-gallon  kettle  or  metal  pail  place  the  10 
pounds  white  arsenic,  then  add  one-half  gallon  of  cold  water  in  small  quantities  at  a 
time,  and  stir  with  a  broad  paddle  until  all  the  arsenic  is  wet.  Place  the  4  pounds  of 
caustic  soda  in  a  gallon  paiJ,  add  one-half  gallon  of  water,  and  stir  until  the  caustic  soda 
is  practically  all  dissolved.  I^ean  the  top  end  of  the  broad  paddle  against  the  top  of  the 
kettle  containing  the  arsenic  and  without  delay  begin  adding  the  caustle-soda  solution  in 
small  portions,  allowing  it  to  run  down  the  surface  of  the  broad  paddle  Into  the  arsenic 
in  such  !i  way  as  to  avoid  splashing.  If  the  solution  begins  to  boil  eonsideralily  stop 
adding  the  caustic-soda  solution  for  a  moment.  Occasionally  stir  the  mixture  while  the 
caustic-soda  solution  is  being  added,  after  which  continue  to  stir  until  all  the  arsenic  Is 
dissolved.  Without  allowing  the  licjuid  to  cool,  add  the  sjU  soda  and  stir  for  a  tvst 
moments,  then  add  1  gallon  of  water  and  continue  to  stir  until  the  sal  soda  is  com- 
pletely dissolved."  .Nccording  to  I>r.  (irafke,  this  method  is  preferred  by  a  considerable 
number  of  experienced  mm. 


Cattle-Fever  Ticks.  25 

Arsenic  stock  requites  the  following  materials  ready  to  hand 
before  starting: 

Pounds. 

Caustic  soda 4 

Wliite  arsenic -_ 10 

Sal-soda  crystals 10 

There  should  be  also  some  means  for  heating  the  solution  in  case, 
as  sometimes  happens  because  of  impure  materials,  lack  of  skill,  or 
some  unforeseen  circumstance,  the  heat  created  by  mixing  the  ma- 
terials should  be  insufficient  to  dissolve  all  the  arsenic. 

In  a  5-gallon  kettle  or  metal  ^  pail  place  the  4  pounds  of  caustic 
soda,  add  1  gallon  of  cold  water,  and  stir  with  a  stick  until  the  caustic 
soda  is  practically  all  dissolved.  Without  delay  begin  adding  the 
white  arsenic,  in  portions  of  a  pound  or  two  at  a  time,  as  fast  as  it 
can  be  dissolved  without  causing  the  solution  to  boil,  stirring  all  the 
time.  If  the  liquid  begins  to  boil,  stop  stirring  and  let  it  cool  slightly 
before  adding  more  arsenic.  The  secret  of  success  is  to  work  the 
arsenic  in  fast  enough  to  keep  the  solution  very  hot — nearly  but  not 
quite  at  the  boiling  point.  The  result  should  be  a  clear  solution, 
except  for  dirt.  If  the  lic^uid  persistently  remains  muddy  or  milky, 
it  may  be  because  the  operation  has  been  conducted  so  fast  that  much 
water  has  been  boiled  out  and  sodium  arsenite  is  beginning  to  crys- 
tallize, so  add  another  gallon  of  water  and  stir.  If  the  solution  does 
not  then  clear  up,  the  caustic  soda  must  have  been  very  low  grade, 
and  the  undissolved  substance  must  be  arsenic.  In  that  case,  put 
the  kettle  over  the  fire,  heat  nearly,  but  not  quite,  to  boiling,  and  stir. 
As  soon  as  the  solution  of  arsenic  is  complete,  dilute  to  about  4  gal- 
lons, add  the  sodium  carbonate,  and  stir  until  dissolved. 

Cautions:  It  is  necessary  to  avoid  splashing.  Hence  never  work  hniTiedly; 
stir  deliberately  and  re^larly ;  do  not  dump  in  the  arsenic  and  sal  soda,  but 
carefully  slide  them  in  from  a  grocer's  scoop  held  close  to  the  side  of  the  pail 
and  to  the  surface  of  the  liquid.  Perform  the  whole  operation  in  a  well-ven- 
tilated place  and  avoid  inhaling  steam. 

After  the  solution  has  become  cold  add  water  to  make  it  to  exactly 
5  gallons,^  mix  well,  let  settle,  and  draw  off  into  containers  which 
can  be  tightly  corked  or  otherwise  closed.  Jugs  or  demijohns  are 
best,  but  tin  cans  will  serve  if  occasionally  inspected  for  leaks  which 
may  occur  after  a  time  through  the  action  of  the  solution  upon  the 
solder  of  the  can. 

1  The  chemicals  employed  have  no  effect  upon  iron.  They  will,  however,  actively  cor- 
rode zinc,  tin,  or  solder  ;  hence  a  soldered  pail  must  be  watched  for  leaks  and  is  far 
inferior  to  a  seamless  pail,  stamped  from  a  single  sheet  of  iron.  A  tinned  pail  is  pre- 
ferred to  a  galvanized  one,  but  a  plain  iron  seamless  pail  or  an  iron  kettle  should  be 
obtained  if  possible. 

2  Best  done  by  previously  determining  by  measurement  the  depth  of  5  gallons  of  water 
in  the  kettle.     Set  the  kettle  exactly  level  and  mark  the  depth  on  a  stick  held  vertically 

1  the  center  of  the  bottom. 


26  Farmers'  Bulletin  i057. 

Tar  stock  is  prepared  thus : 

In  a  large  metal  pail  dissolve  three-fourths  of  a  pound  of  caustic 
soda  in  1  quart  of  Avater,  add  1  gallon  of  pine  tar,  and  stir  thoroughly 
with  a  wooden  paddle  until  the  mixture,  which  at  first  looks  streaked 
and  muddy,  brightens  to  a  uniform,  thick  fluid  somewhat  resembling 
'molasses.  Test  it  by  letting  about  a  teaspoonful  drip  from  the  pad- 
dle into  a  glass  of  water  (a  glass  fruit  jar  or  a  wide-mouth  bottle  will 
do)  and  stirring  thoroughly  with  a  sliver  of  wood.  It  should  mix 
perfectly  with  the  water.  Globules  of  tar  which  can  be  seen  by 
looking  at  the  glass  from  underneath  and  which  can  not  be  blended 
with  the  water  by  repeated  stirring  indicate  that  more  caustic-soda 
solution  is  needed.  In  that  case  make  up  more  caustic-soda  solution 
of  the  same  strength  and  add  it,  not  more  than  a  pint  at  a  time,  with 
thorough  stirring,  until  the  desired  effect  is  produced. 

If  an  appropriate  glass  vessel  for  making  the  test  is  not  at  hand, 
take  a  little  of  the  mixture  between  the  fingers,  then  dip  the  fingers 
under  water  and  try  to  rub  off  the  tar.  It  should  leave  the  fingers 
perfectly  clean  after  a  little  rubbing  with  water.  If  an  oily  coating 
remains,  more  caustic-soda  solution  is  needed.  Such  an  extra  addi- 
tion of  caustic  soda  will  be  required  only  in  case  of  a  very  low-grade 
chemical  or  a  very  highly  acid  tar.  The  tar  stock  should  be  kept  in 
closed  containers,  such  as  a  pail  with  a  friction  top. 

The  quantity  of  S-B  arsenic  stock  or  of  tar  stock  made  in  one 
operation  can  be  varied  as  desired,  provided  the  above-given  pro- 
portions of  the  ingredients  are  adhered  to.  But  one  should  attempt 
to  work  the  S-B  formula  on  a  larger  scale  only  after  skill  and 
experience  have  been  acquired. 

MAKING  THE  BOILED  DIP. 

.  The  boiled  dip  is  less  convenient  than  the  S-B  dip,  but  the  final 
composition  and  effect  of  dipping  ])aths  prepared  from  the  two  is  the 
same. 

To  make  a  500-gallon  bath  jjrovide: 

Sal-s(Hla   crystals -4  iHninds. 

White    arsenic S  pounds. 

Pine  tar 1  jrallon. 

Put  25  gallons  of  water  into  a  kettle  or  tank  of  from  40  to  50  gal- 
lons' capacity,  heat  to  boiling,  and  add  the  sal  soda.  When  this  has 
dissolved  add  the  white  arsenic,  then  boil  and  stir  for  15  minutes  or 
longer,  until  the  white  arsenic  has  entirely  disappeared.  If  intendeil 
for  immediate  use  cool  to  140°  F.  (by  addition  of  cold  water  if 
desired),  then  pour  in  the  pine  tar  in  a  thin  stream  while  constantly 
and  vigorously  stirring  the  solution.  Immediately  (Muply  the  liquid 
into  the  dipping  vat,  which  has  already  been  ihree-fourtlis  lilled^ 
with  water,  and  stir  thoroughly.  \ 


Cattle-Fever  Ticks.       '  27 

All  the  utensils  must  be  free  from  greasy  or  oily  matter  Avhicli 
would  coat  the  arsenic  and  hinder  its  solution.  The  operati  >n  of 
boiling  requires  constant  attention  to  avoid  loss  by  foaming.  Hard 
water  ma}^  be  used,  but  in  that  case  considerable  undissolved  mate- 
rial which,  howeA^er,  does  not  contain  any  arsenic,  may  be  left  after 
boiling. 

For  a  stock  solution  to  be  kept  on  hand  and  used  when  needed  add 
no  tar,  but  after  the  solution  has  become  cold  make  it  up  to  25 
gallons,  stir  well,  let  settle,  and  draw  off  into  containers  which  can 
be  well  closed.  In  this  case  the  tar  stock  previously  described  is  also 
required. 

DILUTING   THE   DIP   TO    FORM   A   BATH. 

First  run  water  into  the  vat  about  three- fourths  up  to  the  dipping 
line,  at  which  its  capacity  must  be  laiown.  If  tar  stock  is  to  be  used 
the  necessary  amount  will  be  one-third  of  a  gallon  for  every  100  gal- 
lons of  vat  capacity.  Measure  it  out,  mix  it  with  2  or  3  times  its 
volume  of  water  and  pour  it  along  the  surface  of  the  water  in  the  vat, 
stirring  a  little. 

Every  100  gallons  of  standard-strength  ^  bath  calls  for  If  pounds 
white  arsenic,  which  quantity  is  contained  in  four-fifths  of  a  gallon 
of  S-B  stock  or  in  5  gallons  of  boiled  stock.  From  these  figures  the 
quantity  of  arsenic  or  stock  needed  to  charge  the  vat  may  be  cal- 
culated.    Or  one  may  base  the  calculation  on  the  following  facts: 

One  pound  of  white  arsenic  will  make  62|  gallons  of  bath. 

One  gallon  of  S-B  stock  will  make  125  gallons  of  bath. 

One  gallon  of  boiled  arsenic  stock  will  make  20  gallons  of  bath. 

All  solutions  of  arsenic  are  considerably  heavier  than  water  and 
if  carelessly  put  into  the  vat  they  may  plunge  to  the  bottom  and 
be  difficult  to  mix.  Therefore  alwaj's  pour  the  arsenic  stock  or  a 
proprietary  dip  in  a  thin  stream  evenly  along  the  vat  except  at 
the  shallow  exit  end.  Another  precaution  to  be  taken  in  handling 
proprietary  dips  is  never  to  mix  them  first  with  small  quantities 
of  water,  which  may  "break"  them.  Pour  them  directly  into  the 
water  in  the  vat. 

Finally  add  water  up  to  the  clipi^ing  line  and  stir  well.  An  ex- 
cellent way  to  stir  is  by  a  pail  tied  to  a  rope.  Sink  it  at  the  en- 
trance end  of  the  vat  and  haul  it  along  the  bottom  to  the  exit.    Then 

1  The  standard  strength  here  referred  to  is  that  employed  throughout  the  area  in  which 
cooperative  tick  eradication  is  conducted.  It  is  based  on  the  supposition  that  the  cattle 
will  be  dipped  every  two  weeks  throughout  the  season  and  meanwhile  will  remain  under 
quarantine.  If,  however,  they  are  to  leave  the  quarantined  area  special  precautions 
must  be  taken  that  they  carry  no  tick  infection,  and  consequently  they  are  subjected  to  a 
stronger  dip,  namely,  from  0.22  to  0.24  i)er  cent  arseulous  oxid.  The  dipping  must  be 
done  under  supervision  of  an  employee  of  the  Bureau  of  Animal  Industry  and  in  accord- 
ance with  regulations  published  in  B.  A.  I.  Order  263. 


28 


•  Farmers'  Bulletin  1057. 


raise  .^t,  throw  it  back  to  the  entrance  end,  and  haul  through  again, 
repealing  as  many  times  as  necessary  but  always  hauling  through  in 
the  same  direction. 

The  standard-strength  bath  prepared  as  above  contains  practically 
0.19  per  cent  arsenious  oxid  when  fresh.  After  use  oxidation  may 
set  in  and  weaken  it,  but  it  will  not  need  to  be  strengthened  so 
long  as  it  tests  not  less  than  0.175  per  cent  arsenious  oxid. 

To  make  up  small  quantities  for  spraying,  to  each  5  gallons  of 
water  measured  out  add  first  2  fluid  ounces  (4  tablespoonfuls)  of 
tar  stock,  and  then  5^  fluid  ounces  of  S-B  stock  or  2{  pints  of 
boiled  arsenic  stock. 

The  standard  strength  of  bath  should  be  adhered  to  so  far  as 
possible  because  its  effectiveness  against  ticks  will  effect  eradica- 
tion in  the  least  time  and  with  fewest  dippings.  But  if  time  is 
not  pressing  it  is  sometimes  best  to  begin  with  a  lower  strength,  say 
0.14  or  0.15  per  cent,  and  gradually  work  up  to  full  strength  as 
the  cattle  become  accustomed  to  the  treatment.  This  is  certainly 
a  wise  method  for  the  individual  cattle  owner  who  is  outside  the 
area  of  cooperative  work  and  who  lacks  aid  and  advice  from  ex- 
perts*. Weather  conditions  also  need  to  be  considered.  Hot  or  moist 
weather  is  more  trying  to  the  cattle  than  cool  or  dry  weather.  The 
longer  the  time  needed  for  the  cattle  to  dry  off  after  dipping,  which 
of  course  primarily  depends  on  the  proportion  of  moisture  in  the 
air,  the  more  liable  they  are  to  sho*w  blistering  or  other  injury 
through  the  continued  absorption  of  arsenic  by  the  skin.  The  com- 
bination of  heat  and  moisture  is  particularly  bad  and  under  such 
conditions  it  may  be  desirable,  unless  other  conditions  prohibit,  to 
use  the  bath  somewhat  weaker  than  standard  strength.  The  fol- 
lowing table  shows  the  quantities  of  arsenic  and  stock  solutions  con- 
tained in  100  gallons  of  bath  of  different  strengths,  so  that  the 
quantities  necessary  to  charge  a  vat  of  any  size  at  any  strength  can 
be  found  by  simple  multiplication. 


Taulk   4. — Composition   of   dippituj    hatJis. 


Per  100  gallons  of  bath. 

Per  100  gallons  of  bath.       ! 

Actual 
arsenious 

Actual 
arsenious 

oxid. 

White 

S-B 

Boiled 

1     oxid. 

White 

P-B 

Boiled 

arsenic. 

stoclf. 

stock. 

arsenic. 

sti)ck. 

stock. 

Percent. 

Pounds. 

Gallons. 

Oallons. 

Per  cent. 

Pounds. 

Oallons. 

Oallons. 

0.0,5 

0.42 

0.21 

1.3 

0.15 

1.25 

0.63 

3.9 

.06 

.50 

.25 

1.6 

i          .16 

1.33 

.67 

4.2 

.07 

.58 

.29 

1.8 

.17 

1.41 

.71 

4.4 

.08 

.66 

.33 

2.1 

.18 

1.49 

.75 

4.7 

.09 

.75 

.38 

2.3 

.19 

1.58 

.79 

4.9 

.10 
.U 
.12 
.13 

.S3 
.91 
l.(K) 
1,08 

.42 
.40 

.54 

2.6 
2.8 
3.1 
3.4 

.20 

.21 

.22 

i          .23 

1.66 
1.74 
1.83 
1.91 

.83 
.87 
.92 
.96 

.14 

1.16 

.58 

3.6 

.24 

2.00 

1.00 

Cattle-Fever  Ticks.  29 

REPLENISHING    THE    BATH    AND    CORRECTING    ITS    STRENGTH. 

As  dipping  goes  on  tlie  bath  naturally  needs  replenishing,  and  its 
strength  probably  needs  correction  from  time  to  time.  The  causes 
which  may  lead  to  changes  in  the  strength  of  arsenical  baths,  to- 
gether with  methods  for  making  chemical  tests,  have  been  discussed 
elsewhere.^  Before  leaving  the  vat  after  dipping  one  may  measure  the 
depth  of  the  bath  or  mark  its  level  on  the  side  of  the  vat.  But  even  then 
at  the  next  dipping  one  can  not  be  certain  just  how  much  a  change 
of  level  has  affected  the  strength  of  the  bath.  For  instance  some  of 
the  bath  may  have  leaked  out  from  the  bottom  while  rain  water  has 
run  in  from  the  top.  Furthermore  certain  microorganisms  can  grow 
in  the  bath  in  spite  of  the  presence  of  the  poisonous  arsenic,  and  can 
greatly  affect  its  strength.  As  already  mentioned,  the  active  ingre- 
dient of  the  bath  is  sodium  arsenite.  The  microorganisms  in  the  proc- 
ess of  growth  can  transfer  oxygen  from  the  air  to  the  sodium 
arsenite,  thus  converting  it  to  sodium  arsenate,  a  distinctly  different 
compound  of  arsenic  and  much  less  poisonous  to  ticks. 

The  rate  at  which  a  bath  may  lose  strength  through  oxidation  de- 
pends on  conditions  and  is  very  variable,  but  ordinarily  is  sufficiently 
rapid  to  weaken  the  bath  decidedly  in  a  month  or  two.  There  is, 
also,  a  certain  species  of  microorganism  which  can  grow  in  baths 
through  which  large  numbers  of  cattle  are  passed  frequently  and 
wdiich  operates  in  precisely  the  opposite  manner  froui  those  men- 
tioned above,  namely,  by  reducing  arsenate  to  arsenite,  thus  render- 
ing the  bath  stronger. 

It  is  therefore  plain  that  the  only  sure  way  to  get  proper  results 
from  successive  dippings  in  the  same  bath  is  to  make  a  chemical  test 
of  its  strength  shortly  before  each  dipping.  The  Bureau  of  Animal 
Industry  provides  all  officials  engaged  in  cooperative  eradication 
work  with  outfits  for  making  this  test.  It  is  easily  carried  out  by  a 
properly  qualified  person,  and  the  cattle  owner  who  dips  privately 
should  have  his  baths  tested  in  the  same  way.  If  a  sample  must  be 
sent  away  for  test  certain  precautions  are  necessary.  First  stir  the 
bath  well.  Fill  the  bottle  (not  less  than  one-fourth  pint)  nearly  to 
the  neck  and  at  once  carefully  add  concentrated  formaldehyde  - 
(which  is  cheap  and  can  be  obtained  from  a  druggist)  with  a  medi- 
cine dropper  in  the  proportion  of  5  drops  to  each  one- fourth  pint. 
Cork  tightly  and  send  at  once. 

No  anxiety  need  be  felt  regarding  the  accumulation  of  oxidized 
arsenic  in  the  bath  during  a  single  season's  use.  Experiments  by  the 
Bureau  of  Animal  Industry  have  shown  sodium  arsenate  to  be  far 

1  U.   S.  Department  of  Agriculture  Bulletins   76  and   259. 

-  This  is  to  act  as  a  preservative  against  microorganisms,   which  may  act   much   more 
,  rapidly   in  a  small  sample  than  in  the  original  bath  in  its  comparatively   cool   location 
underground. 


30  Farmers'  Bulletin  1057. 

less  injurious  to  cattle  than  sodium  arsenitc.  Field  experience,  too, 
indicates  that  under  ordinary  conditions,  provided  the  vat  has  been 
cleaned  out  and  freshly  charged  in  the  spring,  danger  of  injury  from 
this  cause  need  not  be  considered. 

In  practice,  baths  nearly  always  are  both  strengthened  and  re- 
plenished in  one  operation  and  it  is  decidedly  the  simplest  and  best 
procedure.  First  run  water  in  up  to  the  dipping  line,  at  whicli 
the  capacitv  is  known,  and  stir  thoroughly.  Take  out  a  sample  and 
test  it  to  determine  the  per  cent  of  arsenious  oxid.  Then  find  out,  by 
referring  to  Table  4,  how  much  arsenic  or  stock,  whichever  is  to  be 
used,  is  actually  contained  in  100  gallons  of  the  bath  as  it  stands. 
Subtract  that  quantity  from  the  quantity  which  corresponds 
to  the  desired  strength  of  bath,  and  multiply  the  remainder  by  the" 
number  of  hundreds  of  gallons  of  vat  capacity.  This  calculated 
quantity  of  stock,  by  strict  mathematics,  is  not  quite  sufficient  to 
reach  the  desired  percentage,  particularly  if  the  comparatively 
weak  boiled  stock  is  used,  but  it  will  be  close  enough  for  all  practical 
l)urposes. 

xVnother  method  of  calculation  which  requires  no  reference  table 
and  is  particularly  useful  when  proprietary  dips  are  employed,  is  the 
following:  If  it  is  not  already  known,  calculate  the  quantity  of 
arsenic  or  concentrate  which  would  be  needed  to  make  up  an  entirely 
fresh  charge  of  the  desired  strength.  Then  determine  the  fractional 
part  of  this  quantity  necessary  to  raise  the  strength  of  the  existing 
bath  to  the  desired  point.  For  example,  suppose  10  gallons  of  a  certain 
proprietary  dip  is  required  for  a  fresh  charge  of  the  vat  to  the  de- 
sired strength  of  0.18  per  cent  arseniouc  oxid,  while  the  strength 
of  the  vat  actually  in  the  vat  is  found  b}^  test  to  be  0.15  per  cent. 
Then  the  bath  is  too  weak  by  0.03  per  cent,  and  three-eighteenths  of 
10  gallons  of  the  dip  will  have  to  be  added. 

In  course  of  time  filth  and  mud  will  accumulate  in  the  bath  to 
such  an  extent  that  the  vat  will  need  to  be  emptied,  cleaned  out  and 
recharged.  Cattle  dipped  in  a  bath  loaded  with  filth  and  mud  will 
necessarily  carry  out  more  bath  on  their  bodies,  and  so  more  arsenic 
than  they  should;  also  they  will  dry  off  more  slowly,  and  very 
naturally  will  be  more  likely  to  be  blistered.  By  the  same  line  of 
reasoning  some  field  men  of  the  Bureau  of  Animal  Industry  say  that 
after  a  vat  has  been  charged  no  more  tar  or  tar  stock  shouKl 
be  added  in  replenishing  the  bath,  particularly  if  work  oxen  are  to 
be  dipped.  From  experience  they  have  come  to  believe  that  tar 
cements  together  the  filth  and  mud  carried  out  by  the  animals  and 
so  increases  the  chance  of  injury.  At  any  rate  it  appears  to  be  good 
])ractice  to  reduce  the  quantity  of  tar  added  as  the  bath  becomes 
dirtier. 


Cattle-Fever  Ticks.  31 

On  similar  grounds  is  based  the  important  general  rule  never  to 
use  in  the  spring  a  bath  carried  over  the  winter.  Such  a  bath  usually 
will  have  become  largely  oxidized  so  that  when  brought  up  to 
strength  as  respects  actual  arsenious  oxid  it  may  be  dangerously 
high  in  total  arsenic.  It  is  at  the  first  one  or  two  dippings  in  the 
spring  that  cattle  are  most  prone  to  suffer  injury,  especially  when 
they  have  come  through  the  winter  in  poor  condition  or  are  still  in 
long  hair.  They  must  therefore  at  least  be  given  the  advantage  of 
being  dipped  in  a  fresh,  clean  bath. 

PRECAUTIONS   IN    THE   USE    OF   ARSENIC   AND    ARSENICAL    DIPS. 

The  fact  that  arsenic  is  a  violent  poison  is  what  renders  it  valuable, 
for  the  fever  tick  is  hard  to  kill.  But,  like  a  keen-edged  tool,  it  may 
be  decidedly  dangerous  if  ignorantly  or  carelessly  handled.  Three 
possibilities  of  danger  must  be  kept  constantly  in  mind;  danger  to 
oneself,  danger  to  other  persons,  danger  to  animals. 

The  dry,  powdered  white  arsenic  should  be  kept  in  a  tightly 
covered  pail,  plainly  labeled.  Paper  bags  are  unsafe  because  they 
easil}^  burst,  and  arsenic  so  scattered  about  looks  harmless  enough. 
In  weighing  or  otherwise  handling  the  arsenic  avoid  raising  dust 
or  breathing  it  in,  if  raised,  and  keep  it  off  the  skin  and  clothing. 
In  mixing  or  boiling  stock  solutions  work  only  in  a  well-ventilated 
place,  and  on  the  windward  side  of  the  kettle  so  that  steam  arising 
from  it  will  not  be  inhaled. 

The  stock  solutions  are  in  some  respects  more  dangerous  than  the 
original  substance  because  the  arsenic  in  them  is  already  in  solution 
and  can  act  very  quickly.  If  any  gets  on  the  skin  or  clothing  it 
must  be  washed  off  without  delay.  Cattle  must  be  kept  away  from 
such  solutions  or  from  anything  that  has  been  in  contact  with  them, 
for  cattle  craving  salt  have  been  poisoned  by  licking  the  outside  of 
leaky  barrels  and  by  licking  the  earth  around  dipping  vats  where 
a  little  concentrate  had  been  carelessly  spilled  in  charging  the  vat. 
All  such  poisoned  earth  must  be  removed,  buried  and  replaced  by 
fresh. 

The  diluted  bath  is  naturally  much  less  dangerous,  but  no  chances 
can  be  taken  with  it.  No  puddles  from  which  animals  may  drink 
should  be  allowed  to  accumulate.  The  persons  who  do  the  dipping 
should  not  allow  the  skin  or  clothing  to  be  wet  by  the  dip  any  more 
or  any  longer  than  absolutely  necessary.  Wlien  spraying,  the  opera- 
tor should  see  to  it  that  neither  he  nor  the  animals  inhale  any  of  the 
spray. 

When  a  vat  is  to  be  emptied  the  approved  practice  is  to  run  thp 
waste  bath  into  a  pit  properly  guarded  by  a  fence,  where  it  will 
gradually  seep  away  under  the  surface  and  do  no  harm,  provided 


32 


Farmers'  Bulletin  1057. 


only  that  seepage  can  not  be  carried  to  a  well,  stream,  or  sj)! 
from  which  an}*  person  or  domestic  animal  may  drink. 

The  sj-mptoms  of  arsenical  poisoning  are  rather  variable  and  ; 
depend  on  the  size  of  the  dose  and  the  method  of  administraiiui 
If  an  animal  sickens  or  dies  shortly  after  dipping  it  by  no  means  fo^ 
lows  that  arsenical  poisoning  or  any  other  effect  of  the  dipping  is  tl 
cause.  Very  few  cattle  relative  to  the  total  number  dipped  have  sui 
fered  undoubted  arsenical  poisoning  and  in  most  of  the  cases  tl 
cause  could  be  traced  to  somebody's  error  or  carelessness. 

In  regard  to  arsenical  poisoning  of  human  beings  there  is  a  stanci 
ard  antidote  which  may  be  obtained  at  any  drug  store  with  direction) 
for  use.  It  should  be  kept  on  hand  for  emergencies.  If  the  antidot| 
is  not  at  hand  the  poison  must  be  removed  from  the  stomach  by  ei 
couraging  repeated  vomiting,  and  soothing  drinks  such  as  millJ 
white  of  eggs  and  water,  or  flour  and  water  must  be  freely  giveJ 
meanwhile.  A  suspected  case  of  arsenical  poisoning  must  have  thj 
attention  of  a  physician  at  the  earliest  possible  moment,  as  some 
times  the  poison  works  very  quickly. 


The  Next  Step- 


The  eradication  of  tlie  cattle  ticl^s  makes  it  possible  to  introduce 
and  grow  more  and  better  cattle  and  to  develop  successful  beef  rais- 
ing and  dairy  farming.  Farmers  in  areas  that  have  been  freed  of 
ticks  or  where  eradication  is  under  way  will  find  helpful  information 
in  the  following  publications: 

Texas  or  Tick  Fever.     (Farmers'  Bulletin  509.) 

P.eef  Production  in  the  South.     (Farmers'  Bulletin  580.) 

Breeds  of  Beef  Cattle.     (Farmers'  Bulletin  (J12.) 

Eradication  of  the  Cattle  Tick  Necessary  for  I'rofitable  Dairying 

(Farmers'  Bulletin  639.) 
Cottonseed  Meal  for   Feeding   Beef  Cattle.      (Farmers'    Bulletin 

055. ) 
The  Feeding  of  DaiiT  Cows.     (Farmers'  Bulletin  743.) 
Feeding   and    Management    of    Dairy    Calvof?   and    Young    Dairy 

Stock.      (Farmers'  Bulletin  777.) 
IMarkcting  Live  Stock  in  the  South.     (Farmers'  Bulletin  809.) 
Production  of  Baby  Beef.     (Farmers'  Bulletin  811.) 
]\Iaking  Butter  on  the  Farm.     (Farmers'  P.ulhMin  870.) 
Breeds  of  Dairy  Cattle.     (Farmers'  Bulletin  S'.C!. ) 
Cooling  Milk  and  Cream  on  the  Farm.     (Fanners'  P>ullelin  97().  i 
Cooperative  Bull  Associations.     (Farnier.s'  P.ulletin  993.) 
The  Story  of  the  Cattle  Fever  Tick.     ( rnnumbereil  publication.) 
"Better  Sires— Better  Stock."     (L.  S.  C.  4.) 

Any  of  the  foregoing  imblications,  so  far  as  available,  may  be  ob- 
tained free  of  churge  on  applicution  to  the  United  States  Department 
of  Agriculture,  Wa.shington,  D.  C. 


WASHINGTON  :  (iOVEUNMBNT  I'llINTING  OFFICI 


I  o  o  ■ 


llenbergei 


T5£5 
"biology 

LIBRAB^ 
G 


RETURN  TO  the  circulation  desk  of  any 
University  of  California  Library 
or  to  the 

NORTHERN  REGIONAL  LIBRARY  FACILITY 
BIdg.  400,  Richmond  Field  Station 
University  of  California 
Richmond,  CA  94804-4698 

ALL  BOOKS  MAY  BE  RECALLED  AFTER  7  DAYS 
2-month  loans  may  be  renewed  by  calling 

(510)642-6753 
1-year  loans  may  be  recharged  by  bringing  books 

to  NRLF 
Renewals  and  recharges  may  be  made  4  days 

prior  to  due  date 

DUE  AS  STAMPED  BELOW 


EB 


iQQ- 


